My experience is that flying Unlimited vs Advanced will burn more oil. There is a auxiliary case mounted oil pump that you can fit that will pump the oil back from the inverted system back into the engine instead off the breather hose. When the breather hose feeds into the 6-1 exhaust you have a suction on the breather hose sucking oil out of the inverted system adding to more oil loss. The MX2 that Rob Holland flew at WAC this year was fitted with this pump reducing 1-2 quarts per 20 flight to zero oil use.